High-pressure balloons can be used to precisely position a device in a vessel or
body cavity. This is a new market for specialty technologies. Elastomeric balloons
are often used for positioning; however, high-pressure balloons are preferred when
a precise shape or position is required. An elastomeric balloon can stretch and
roll shifting back and forth, which is unacceptable in critical positioning applications.
In addition, elastomeric balloons often inflate non-concentrically and unpredictably,
which preclude their use in precision applications.
On the left is a high pressure, thin walled balloon. On
the right is an elastic latex balloon. Elastomeric balloons often unintentionally
expand asymmetrically as seen here.
A balloon can be used to center a device such as radioactive seeds in a vessel to
deliver radiation in hopes of preventing restenosis. Centering the device ensures
symmetrical dosage around the wall. Some procedures concentrate on only one side
of a vessel or cavity, such as directional arthrectomy, which cuts away plaque from
vessel walls. The procedure uses a cutter that spins at high speed inside a housing.
A balloon is mounted to the back of the housing and inflated, pushing the cutter
against the wall of a vessel, allowing it to be debulked.
A directional coronary arthrectomy catheter is shown with
the balloon inflated. The balloon is mounted on the back of the cutter housing and
it is used to push the cutter against plaque.
Source: Guidant Corp
Another example is the treatment of BPH (benign prostate hyperplasia) or enlarged
prostate gland. In this application, an offset balloon can be used to position a
device off to the side, directly against a lobe of the gland, to deliver microwave
or laser energy only where it is needed or conversely a standard balloon can be
used to insure that the device remains centered.
High-pressure balloons are also used to position diagnostic devices in ultrasound
imaging and other techniques that require locating them inside vessels or body cavities.
Rather than having a complicated steering or positioning mechanism on the end of
a catheter, a high-pressure balloon can be used to either center or offset the device,
precisely positioning it as required.
High-pressure balloons designed to be offset (top and
bottom balloons) and centered (middle balloon). Offset balloons can be used to position
various instruments to concentrate on one wall while symmetrical balloons precisely
center an instrument in a body cavity.
A balloon with a narrowing in the body can be used to
position a device laterally within a structure such as a valve. The larger diameter
on either end ensures that the device will not move proximal or distal to any great
degree.